Method and apparatus for producing a fermentation product

Abstract

Provided is a method for producing a fermentation product, the method comprising: a first step of preparing a deionized process liquid by removing ions from a process liquid containing a fermentation product by capacitive deionization (CDI); and a second step of spray-drying the deionized process liquid to obtain a fermentation product without recrystallizing the fermentation product. According to the present disclosure, a fermentation product can be produced in an environmentally friendly manner because an ion exchange resin column is not used, and a high-purity fermentation product can be obtained in a high yield because a reduction in the concentration of the fermentation product in a process liquid due to dilution in an ion removal process can be avoided.

Description

Technical Field

[0001] The present disclosure relates to a production method and apparatus for obtaining a high-purity fermentation product in a high yield in an environmentally friendly manner. Background Art

[0002] Capacitive deionization (CDI) is a technique for removing ions by adsorbing ions onto an electrode having a high specific surface area using an electrochemical principle. When an electric power is applied to the electrode surface, ions are adsorbed, and when the adsorption reaches saturation, ions are no longer adsorbed, so a reverse potential is applied to desorb the ions, thereby regenerating the electrode. Since CDI and MCDI techniques operate at low potentials, they consume low energy. Since CDI and MCDI techniques do not use acids, alkalis, or salts during electrode regeneration, they are regarded as environmentally friendly techniques.

[0003] Patents related to CDI or MCDI include electrode technology, module technology, and application technology, and the application technologies of CDI and MCDI are mainly used for water softeners and seawater desalination devices. 'KR 10-2022-0096174A' describes an electro-deionization type water purifier in which an electro-deionization filter and module are used to purify water. 'KR 10-2333880B1' describes an apparatus and method for continuously supplying purified water using a CDI water purifier. In 'KR-10-1949140', CDI is used to separate ions, and then the separated ions are solidified and the solidified ions are used to manufacture a mineral beverage.

[0004] These patents are mainly about purifying water or collecting ions for ion utilization. Summary of the Invention

[0005] Technical Problem

[0006] When producing fermentation products such as amino acids, peptides, and polyphenols from a fermentation broth, the ions in the product are problematic, and in the present disclosure, it has been confirmed that CDI can also be fully used in this case, and it is intended to apply CDI to the production of food fermentation products or food raw material products from a fermentation broth.

[0007] Technical Solution

[0008] An object of the present disclosure is to provide a method capable of removing ions in an environmentally friendly manner without using an ion exchange resin by a CDI method, thereby producing a high-purity fermentation product in a high yield.

[0009] In addition, another object of the present disclosure is to reduce the process cost during the production of a fermentation product.

[0010] Advantageous Effects

[0011] When using the method and apparatus for producing a fermentation product according to an aspect of the present disclosure, the CDI method can be used to produce the fermentation product in an environmentally friendly manner without using ion exchange resins.

[0012] In addition, according to the present disclosure, since the fermentation product is not diluted by the elution solution, the energy required for drying can be reduced.

[0013] In addition, according to the present disclosure, since the spray drying method is used to produce the fermentation product without crystallization after the deionization process, the generation of mother liquor and the loss of the fermentation product can be reduced, thereby improving the process yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a flowchart showing a method for producing a fermentation product according to the present disclosure;

[0015] Figure 2 is a block diagram showing an apparatus for producing a fermentation product according to the present disclosure;

[0016] Figure 3 is a block diagram showing a CDI apparatus in an apparatus for producing a fermentation product according to an embodiment of the present disclosure;

[0017] Figure 4 is a flowchart showing a method for producing a fermentation product according to the present disclosure; and

[0018] Figure 5 is a graph analyzing the particle size of a fermentation product produced according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0019] The present disclosure will be described in detail below. At the same time, each description and embodiment disclosed in the present disclosure can also be applied to other descriptions and embodiments. That is, all combinations of the various elements disclosed in the present disclosure fall within the scope of the present disclosure. In addition, the scope of the present disclosure is not limited by the specific embodiments described below.

[0020] The present disclosure relates to a technique for producing a fermentation product by the CDI method and spray drying. Since ion exchange resins are not used in the production process, the technique is environmentally friendly, and since the fermentation product is not diluted in the process, the cost associated with the steam drying of the fermentation product can be reduced. In addition, since the fermentation product is produced by a spray drying process after ion removal, a recrystallization process after ion removal is not necessary, and thus, the amount of the generated mother liquor can be reduced, thereby increasing the yield of the fermentation product.

[0021] Figure 1 is a flowchart showing a method for producing a fermentation product according to the present disclosure.

[0022] Refer toFigure 1 , a method for producing a fermentation product according to the present disclosure includes a first step (S100) of preparing a deionized process liquid by removing ions from a process liquid containing the fermentation product via capacitive deionization (CDI); and a second step (S200) of spray-drying the deionized process liquid to obtain the fermentation product without recrystallizing the fermentation product. Hereinafter, each step will be described in detail.

[0023] The first step (S100) is a step of preparing a process liquid containing the fermentation product and preparing a deionized process liquid by removing ions in the process liquid via capacitive deionization (CDI).

[0024] In the first step (S100), a process liquid can be prepared by fermentation using microbial cells. The fermentation product contained in the process liquid can be an amino acid, a peptide, or a polyphenol.

[0025] For example, when the fermentation product is an amino acid, the amino acid can include at least one selected from the group consisting of glycine, alanine, serine, proline, valine, threonine, cysteine, isoleucine, leucine, asparagine, aspartic acid, glutamine, lysine, glutamic acid, methionine, histidine, phenylalanine, selenocysteine, arginine, tyrosine, citrulline, ornithine, and tryptophan. The fermentation product that can be produced according to the present disclosure can be any substance as long as it is not adsorbed together with ions during the CDI process. In some cases, the fermentation product contained in the process liquid can be at least one selected from the group consisting of leucine, citrulline, isoleucine, and valine.

[0026] The process liquid prepared in the first step (S100) can be a fermentation substance produced by a strain. As used herein, the term "fermentation substance" refers to a product obtained by enzymatic decomposition or metabolic decomposition of an organic substance using microorganisms. For example, the fermentation substance can include the culture itself obtained by culturing microorganisms in a culture medium, or a concentrate, dried product, or lyophilized product of the culture obtained by removing the microorganisms therefrom. In addition, in this case, the fermentation broth can contain all the fermentation substances containing the fermentation product, or can be a fermentation substance containing the fermentation product from which impurities have been removed.

[0027] The "microorganisms producing the fermentation product" or "microorganisms producing the fermentation product or the target product" used in the first step (S100) include wild-type microorganisms and microorganisms that have been genetically modified naturally or artificially, and can be microorganisms in which a specific mechanism is weakened or strengthened due to the insertion of foreign genes or the enhancement or inactivation of endogenous gene activities, etc., and it can be a microorganism containing genetic modifications for producing the target protein or fermentation product.

[0028] The microorganism for producing the fermentation product of the present disclosure may be a microorganism that naturally has the ability to produce the fermentation product, or a microorganism prepared by conferring the ability to produce the fermentation product to a parental strain that does not have the ability to produce the fermentation product, but is not limited thereto. Specifically, in the present disclosure, the microorganism that produces the fermentation product or the target product, or has the ability to produce the fermentation product or the target product, may be a microorganism in which some genes involved in the biosynthetic pathway of the target protein or the target product are enhanced or weakened, or some genes involved in the degradation pathway of the target protein or the target product are enhanced or weakened. The "enhancement" or "increase" of the fermentation product production ability of the microorganism of the present disclosure means that the fermentation product production ability of the microorganism of the present disclosure is improved compared to a microorganism, a parent strain, or an unmodified microorganism other than the microorganism of the present disclosure. For example, compared with the fermentation product production ability of other microorganisms, the fermentation product production ability of the microorganism of the present disclosure may be increased by about 1% or more, 10% or more, 100% or more, 200% or more, 500% or more, 1000% or more, 1100% or more, 1200% or more, or 1300% or more, and increased by about 1.01-fold or more, 2-fold or more, 5-fold or more, 10-fold or more, 11-fold or more, 12-fold or more, or 13-fold or more, but is not limited thereto. The term "about" includes all ranges such as ±0.5, ±0.4, ±0.3, ±0.2, ±0.1, etc., and includes all values within the range equivalent to or similar to the value after the term "about", but is not limited thereto.

[0029] The above-mentioned microorganism used in the first step (S100) may be at least one selected from the group consisting of Candida famata, Eremothecium ashbyii, Ashbya Gossypii, Bacillus subtilis, and Corynebacterium sp.

[0030] When the microorganism used in the first step (S100) is a microorganism of the genus Corynebacterium, the microorganism may specifically be Corynebacterium glutamicum, Corynebacterium crudilactis, Corynebacterium deserti, Corynebacterium efficiens, Corynebacterium callunae, Corynebacterium stationis, Corynebacterium singulare, Corynebacterium halotolerans, Corynebacterium striatum, Corynebacterium ammoniagenes, Corynebacterium pollutisoli, Corynebacterium imitans, Corynebacterium testudinoris, Corynebacterium crenatum or Corynebacterium flavescens, and more specifically, Corynebacterium glutamicum, but not limited thereto.

[0031] The first step (S100) may further include a step of culturing the "microorganism for producing a fermentation product". The culturing of the microorganism may be carried out according to suitable culture media and culture conditions known in the art. Those skilled in the art can easily adjust and use such a culturing method based on the selected strain. Specifically, the culturing may be batch type, continuous type, and fed-batch type, but not limited thereto. As used herein, the term "culture medium" refers to a mixture containing nutrients required for culturing microorganisms as the main components, wherein the culture medium provides water, nutrients, growth factors, etc. necessary for survival and growth. In particular, for the culture medium and other culture conditions for culturing the microorganisms of the present disclosure, any culture medium commonly used for culturing microorganisms may be used without particular limitation. However, the microorganisms of the present disclosure can be cultured under aerobic conditions in a general culture medium containing a suitable carbon source, nitrogen source, phosphorus source, inorganic compound, fermentation product, and / or vitamin, etc., while controlling the temperature, pH, etc.

[0032] In the first step (S100), the capacitive deionization (CDI) process refers to the process of removing ionic substances from a process liquid by adsorbing the ionic substances onto electrodes. The CDI process can be carried out by flowing the above-mentioned process liquid through the electrodes while applying an electric potential to the electrodes. In this process, the fermentation products contained in the process liquid pass through along the flow path without being adsorbed onto the electrodes and are supplied to the second step (S200), and the ionic impurities are adsorbed onto the electrodes and thus removed. CDI is a technique that uses the electrochemical principle to remove ions by adsorbing ions in the electric double layer on the surface of electrodes with a high specific surface area. When an electric power is applied to the electrode surface, ions are adsorbed, and when a reverse electric potential is applied, the ions are desorbed, which regenerates the electrodes. Since the CDI technique operates at a low potential of about 1.2 V, the energy consumption is low, and since it does not use acids, alkalis, or salts when regenerating the electrodes, it is environmentally friendly.

[0033] The CDI process carried out in the first step (S100) can sometimes be carried out by a membrane capacitive deionization device (MCDI), which is a modified form of the general CDI process. The membrane capacitive deionization device (MCDI) is characterized by forming an ion exchange membrane on the electrode surface to increase the selectivity of the ions to be adsorbed. Therefore, in the present disclosure, when referred to as the CDI process, it includes the general CDI process or the modified MCDI process.

[0034] The impurities removed by CDI in the first step (S100) can be chloride ions (Cl - ), phosphate ions (PO4 3- ), sulfate ions (SO4 2- ), sodium ions (Na + ), ammonium ions (NH4 + ), potassium ions (K + ), calcium ions (Ca 2+ ), magnesium ions (Mg 2+) or polar organic substances. Both cations and anions can be removed through the CDI process. Therefore, different from the prior art that requires both a process through cation exchange resin and a process through anion exchange resin to remove cations and anions, ions can be removed by a single step of injecting the process liquid into the CDI process, thereby improving the treatment efficiency. In addition, since ion exchange resin is not required, there is no need for a chemical solvent for desorbing the ions adsorbed on the ion exchange resin and regenerating the resin, thus producing the fermentation product in an environmentally friendly manner. In addition, compared with the method of separating impurities by adsorbing the fermentation product onto chromatography, the above method requires an elution solution to separate the fermentation product adsorbed on the chromatography, and during this process, the concentration of the fermentation product is diluted by the elution solution. In addition, chemicals (such as caustic substances or hydrochloric acid, etc.) are also required. For this reason, a large amount of energy (such as steam, etc.) is required to remove the large amount of elution solution mixed with the fermentation product. In contrast, the method of using CDI to remove impurities does not use an elution solution, so the concentration of the fermentation product in the deionized process liquid can remain unchanged before and after removing the impurities. Therefore, after the CDI process, the energy required for drying to obtain the fermentation product is low, and the fermentation product can be obtained more economically.

[0035] In the first step (S100), after the CDI process is carried out, only 200 ppm or less of ions, including positive / negative ions, can be provided in the deionized process liquid.

[0036] The pH of the process liquid in the first step (S100) can be 3 to 11. Within the acidity range of the above process liquid, the fermentation product can be electrically neutral without being ionized.

[0037] In the first step (S100), process liquid can be introduced into the CDI process at a rate of 1.3 L / min to 5 L / min. As the flow rate of the process liquid becomes slower, the time for the electrode and the process liquid to meet becomes longer, so more ions contained in the process liquid can be adsorbed and removed. However, when the flow rate of the process liquid becomes lower than 1.3 L / min, the process liquid treatment speed may be excessively reduced, which may adversely affect the treatment yield. On the contrary, when the flow rate of the process liquid becomes faster, the process liquid treatment speed increases, while the time for the process liquid and the electrode to meet becomes shorter. Therefore, relatively fewer ions contained in the process liquid can be removed. Thus, by controlling the flow rate of the process liquid within 1.3 L / min to 5 L / min, ionic impurities contained in the process liquid can be sufficiently removed while ensuring the treatment yield. As a range for achieving the above object, the flow rate of the process liquid can be 1.3 L / min to 2.6 L / min or 2.6 L / min to 5.0 L / min. The flow rate of the process liquid can be determined by considering process factors such as the concentration of ionic impurities contained in the process liquid within the above range, the amount of the process liquid, etc.

[0038] After performing the first step (S100), a step of regenerating the electrode by desorbing the ions adsorbed to the electrode during the CDI process can also be performed. The step of regenerating the electrode can be carried out by applying a potential opposite to the potential applied when adsorbing the ions to the electrode to desorb the ions. At this time, a solvent (such as water, etc.) can be applied to the flow path to remove the desorbed ions.

[0039] In the first step (S100), a filtration and decolorization process can also be performed on the fermentation broth. Impurities can be further removed by filtration and decolorization. The filtration and decolorization process can be carried out by general methods and can be omitted if necessary to simplify the process.

[0040] Before performing the first step (S100), a step of crystallizing and dissolving the fermentation product contained in the process liquid can also be performed. By crystallizing and dissolving the fermentation product, impurities contained in the fermentation broth can be preliminarily removed. However, if necessary, this process can be omitted to simplify the process.

[0041] Then, the deionized process liquid prepared by removing ionic impurities in the first step (S100) is introduced into a spray drying process.

[0042] In the second step (S200), the deionized process liquid is spray dried to obtain a fermentation product without recrystallizing the fermentation product.

[0043] Spray-drying, also known as spraying drying, is a method that can simultaneously accomplish drying and granulation. It is a method that can directly dry solutions, emulsions, and suspensions into powder or granular products, thus eliminating evaporation, grinding, and other processes. After spray-drying, the fermentation product can be dispersed into particles, and most of the moisture can be removed, enabling the fermentation product in the deionized process liquid to be dried into powder.

[0044] Spray-drying is a method of immediately obtaining a dried product in the liquid phase by spraying a liquid into a hot air stream, which includes centrifugal spraying using a rotating disk and pressure spraying using a pressure nozzle, but is not limited thereto.

[0045] During the spray-drying process, it can be carried out as follows: for example, setting the inlet temperature of the hot air at 120°C to 250°C and its outlet temperature at 30°C to 150°C, preferably 50°C to 100°C, but not limited thereto.

[0046] When obtaining a fermentation product using spray-drying, there is no need for the process of recrystallizing the deionized process liquid containing the fermentation product and separating the crystalline fermentation product as in the existing methods. As described above, in the case of the prior art, the problem is that even after the deionization process, many impurities still remain in the process liquid, or the concentration of the fermentation product becomes low as the fermentation product is diluted by the elution solution after the deionization process. Therefore, in order to obtain a high-purity fermentation product, a process of crystallizing and separating the fermentation product is required. However, when separating the fermentation product by crystallization, it is said that the fermentation product may be lost during the crystallization and crystal separation processes.

[0047] On the contrary, in the present disclosure, the concentration of the fermentation product during the deionization process does not decrease, but only ionic impurities are removed. Therefore, the concentration of the fermentation product before and after deionization is the same. Thus, a high-purity fermentation product can be obtained without crystallizing the fermentation product. In addition, since no elution solution is added during the deionization process, the moisture content is relatively low, making it suitable for introduction into the spray-drying process. When using an elution solution as in the prior art, the moisture content in the process liquid increases, and it may be difficult to completely evaporate the moisture by spray-drying.

[0048] According to the present disclosure, ionic impurities can be removed without using an ion exchange resin, and a high-purity fermentation product can be obtained in an environmentally friendly manner with high yield by using the CDI method and the spray-drying method. In addition, according to the present disclosure, since there is no need for the process of crystallizing the deionized process liquid, the generation of the remaining solution (mother liquor) after removing the fermentation product can be reduced.

[0049] According to the present disclosure, a high fermentation product recovery rate of 95% or higher can be ensured.

[0050] Figure 4 is a flowchart depicting a method for producing a fermentation product according to the present disclosure.

[0051] According to Figure 4 , after performing the first step (S100) of preparing a deionized process liquid by CDI, the third step (S300) of crystallization is performed.

[0052] Since the details of the first step (S100) are the same as those discussed above Figure 1 , they are omitted below to avoid repeated explanations.

[0053] The crystallization in the third step (S300) is a step of obtaining a fermentation product in crystalline form by crystallizing the process liquid from which ionic impurities have been removed. The crystallization in the third step (S300) can be carried out by various methods, and there is no limitation on the method. For example, the crystallization in the third step (S300) can be carried out by various methods (such as adding a coagulant, adjusting the pH, cooling, concentrating, etc.). In addition, various solid-liquid separation methods (such as separation using a basket, centrifugation, etc.) can be used to separate the crystalline fermentation product.

[0054] Therefore, as described above, the CDI method exhibits excellent effects in removing ionic impurities without diluting the process liquid, and this method does not necessarily have to be used together with the spray drying method. The CDI method can be combined with various crystallization methods and subsequent methods.

[0055] Above, a method for producing a fermentation product according to one aspect of the present disclosure has been described. Below, an apparatus capable of performing the above process for producing a fermentation product will be described.

[0056] Figure 2 is a block diagram showing an apparatus for producing a fermentation product according to the present disclosure, and Figure 3 is a block diagram showing a CDI apparatus inside an apparatus for producing a fermentation product according to an embodiment of the present disclosure.

[0057] Referring to Figure 2 , an apparatus includes a capacitive deionization (CDI) apparatus (100) for preparing a deionized process liquid by removing ions from a process liquid containing a fermentation product; and a spray drying apparatus (200) for obtaining a fermentation product from the deionized process liquid prepared by the CDI apparatus without recrystallization.

[0058] Referring to Figure 3, the CDI device (100) may include: an electrode element 120 for adsorbing and removing ions contained in the process liquid when power is applied; and a flow path element (110) configured such that the process liquid is discharged to the outside of the CDI device (100) after contacting the electrode element (120).

[0059] The flow path element (110) may be in the form of a straight line extending in one direction as shown in the figure, but may be implemented in various configurations if necessary to increase the time of encounter between the electrode element (120) and the process liquid.

[0060] The flow path element (110) may be made of a material with low reactivity so as not to react with the process liquid. Inside the CDI device (100), the flow path element (110) may be provided individually or may be provided as multiple elements in parallel. The number, configuration, size, etc. of the flow path element (110) may be determined in view of the purpose of treatment, treatment capacity, etc.

[0061] The electrode element (120) may be connected to a power supply element such that a potential can be applied thereto. The power supply element may be provided inside or outside the CDI device (100). The electrode element (120) is arranged adjacent to the flow path element (110). In some cases, as shown in the figure, a pair of electrode elements (120) may be arranged such that each contacts the flow path element (110). In this case, the pair of electrode elements (120) may have potentials in different directions. For example, the potential of the (+) pole may be applied to one electrode, while the potential of the (-) pole may be applied to the other electrode. Thus, anion impurities and cation impurities contained in the process liquid can all be adsorbed onto the electrode element (120) and thus removed. The direction of the potential applied to the electrode element (120) may vary according to the operation of the power supply element. Thus, the electrode element (120) can adsorb or desorb ionic impurities.

[0062] The electrode element (120) may have a high specific surface area. For example, the electrode element (120) may include a porous surface or an uneven structure. By utilizing the electrochemical principle of the adsorption reaction of ions in the electric double layer on the surface of the electrode element (120) with a high specific surface area, ions can be adsorbed and removed.

[0063] The spray drying device (200) may include an air heating element, a nozzle, a drying device, a product recovery device, etc. The nozzle may be a device that atomizes a liquid process fluid into liquid particles of a desired size, sprays the liquid particles, and disperses them into a high-temperature air stream. The solvent in the sprayed liquid particles instantaneously evaporates in the high-temperature air stream, and high-purity fermentation product particles can be produced. The fermentation product particles can move through the air stream to the product recovery device and then be recovered. The product recovery device may generate a suction air stream in the drying chamber to recover the fermentation product particles.

[0064] In some cases, the CDI device (100) may be implemented in the form of a membrane capacitive deionization device (MCDI). In this case, an anion exchange resin may be disposed at the positive electrode of the electrode element (120) included in the CDI device (100), and a cation exchange resin may be disposed at the negative electrode.

[0065] Above, a device for producing a fermentation product according to an aspect of the present disclosure has been described. The device for producing a fermentation product according to the present disclosure can produce a high-purity fermentation product in an environmentally friendly manner and at a high yield by using the CDI device (100) and the spray drying device (200).

[0066] Embodiments of the present invention

[0067] Hereinafter, the present disclosure will be described in more detail through exemplary embodiments. However, the following exemplary embodiments are merely preferred embodiments for illustrating the present disclosure, and thus are not intended to limit the scope of the present disclosure thereto. Meanwhile, technical matters not described in this specification can be fully understood and easily implemented by those skilled in the technical field of the present disclosure or similar technical fields.

[0068] Above, a method and a device for producing a fermentation product according to an aspect of the present disclosure have been described. Hereinafter, the beneficial effects mentioned in the present disclosure are intended to be described through the experimental results of examples and comparative examples.

[0069] Example 1: Analyzing the deionization rate and the recovery rate of the fermentation product using CDI

[0070] An experiment was conducted using a 100-L scale CDI device, and the applied flow rate was 5 L / min. When the feed was applied to the CDI device, the ion adsorption and desorption processes were repeated.

[0071] An experiment was conducted using a 100-L scale CDI device and operating at 5 L / min, and a mixture of leucine, isoleucine, and valine containing ions was used as the feed solution. At this time, the deionization rate was 83% to 88%. Through conductivity and Na + and SO4 2-The deionization rate is measured by the concentration of . The recovery rate of the fermented product amino acids in Example 1 is about 98% to 100%. Even when three types of fermented products (such as leucine, isoleucine, and valine) are mixed, the recovery rate of the fermented product is at the same level of 98% to 100%. In addition, the concentration of the fermented product in the adsorption solution is the same as that in the feed, confirming that the fermented product is not diluted despite the removal of ions. When the fermented product is not diluted, steam for additional concentration is not required, so the steam cost can be reduced.

[0072] [Table 1]

[0073]

[0074] Example 2: Analyze the deionization rate and the recovery rate of the fermented product according to the CDI flow rate

[0075] For a 100-L scale CDI device, experiments are carried out by adjusting the flow rate to 1.3 L / min and 2.6 L / min. For the process liquid, a solution in which citrulline crystals are dissolved is used. As a result of the experiment, when the flow rate changes from 2.6 L / min to 1.3 L / min, the deionization rate tends to increase from 63% - 66% to 79% - 82%. Regardless of the change in the flow rate, the recovery rate of the fermented product is 100%.

[0076] Based on these results, as the flow rate decreases, the deionization rate is expected to increase, but the hourly throughput of the process liquid decreases. Therefore, it seems that the optimal flow rate should be determined according to the hourly throughput and the deionization rate.

[0077] [Table 2]

[0078]

[0079] Example 3: Operating conditions and product quality during spray drying after CDI deionization

[0080] The citrulline dissolution solution deionized by CDI in Example 2 is used for spray drying. During the spray drying process, a nozzle-type spray dryer is used for drying under the conditions of an inlet temperature of 200 °C and an outlet temperature of 90 °C.

[0081] [Table 3]

[0082]

[0083] After drying under the corresponding conditions, it is confirmed that the moisture content in the powder is less than 0.2%, the recovered citrulline reaches a content of 98.5%, the Cl - content is 0.02% or less, and the NH4 +The content is 0.02% or lower, indicating that ions in the dry citrulline crystals can be removed. At this time, as Figure 5 shown, the median particle size is about 27.1 μm.

[0084] Comparative Example 1: Method for removing anions and separating citrulline using a cation resin

[0085] To remove cells from the fermentation broth, the pH was adjusted to 4 using sulfuric acid, and the cells were separated using membrane separation. The ions in the cell separation solution were present at 14.6% based on the total solid weight. In this regard, since anions were the main ions, a cation resin was used to separate the ionic impurities. The pH was adjusted to 1 using sulfuric acid to adsorb citrulline onto the cation resin by cationizing citrulline. The cell separation solution with the pH adjusted to 1 was passed through a cation resin column to adsorb citrulline, and then washed with water to remove impurities other than cations in the cell separation solution. Thereafter, citrulline was separated by eluting with 0.1N sodium hydroxide solution. When separating citrulline using a cation resin in this way, anions were completely removed, so impurities based on 9.8% of the total solid weight could be separated. However, the drawback is that it is difficult to separate 4.8% of the cations based on the total solid weight and the use of chemicals (such as sulfuric acid, sodium hydroxide, etc.). When using chemicals, it is not ideal in terms of ESG, and there is a drawback of increasing the refining material cost due to the use of chemicals.

[0086] [Table 4]

[0087]

[0088] Comparative Example 2: Method for removing ions using a chromatographic resin

[0089] It was observed that when purifying the feed using chromatography, the deionization rate was 98%, meaning that ions could be removed at a high level. However, in terms of the citrulline concentration, the citrulline concentration was 110 g / L, and when transferred to the process liquid after removing ions from the feed, it was diluted to 28.9 g / L, a value that decreased by about 3.8 times. Therefore, although chromatography is effective in ion removal, the problem is that due to the dilution of the fermentation product in the process liquid, additional steam costs are required in the final production process.

[0090] [Table 5]

[0091]

[0092]

[0093] Comparative Example 3: Method for removing ions using crystallization

[0094] Table 6 shows the data obtained by removing ions from the feed through the crystallization process to obtain only citrulline crystals. At this time, the deionized process liquid (SMB extract) obtained by removing ions through continuous chromatography was used as the feed, and cooling crystallization was carried out at 35 °C. At this time, the deionization rate of citrulline crystals in the feed was 90.9%, and the crystal recovery rate was 80.32%. Since it was 0.02% lower than the citrulline product specification standard, citrulline crystals that met all product specifications could be produced. However, when removing ions by crystallization, the recovery rate was 80%, resulting in a 20% loss of citrulline, and crystallization mother liquor was produced during crystal separation. This mother liquor must be recycled back to the upstream process or treated as wastewater, which is environmentally unfavorable and increases costs due to wastewater treatment.

[0095] [Table 6]

[0096]

[0097] Based on the above description, those skilled in the art will understand that the present disclosure can be implemented in different specific forms without changing its technical spirit or essential features. In this regard, it should be understood that the above embodiments are not restrictive but illustrative in all aspects. The scope of the present disclosure is defined by the appended claims rather than by the description following them. Therefore, all changes and modifications that fall within the boundaries and scope of the claims, or within the equivalents of these boundaries and scope, are intended to be encompassed by the claims.

Claims

1. A method for producing a fermentation product, the method comprising: a first step of preparing a deionized process liquid by removing ions from a process liquid containing the fermentation product through capacitive deionization (CDI); and a second step of spray-drying the deionized process liquid to obtain the fermentation product without recrystallizing the fermentation product.

2. The method according to claim 1, wherein the fermentation product comprises one or more selected from the group consisting of leucine, isoleucine, citrulline, and valine.

3. The method according to claim 1, wherein in the first step, the process liquid is introduced into the CDI process at a rate of 1.3 L / min to 5 L / min.

4. The method according to claim 1, further comprising, after performing the first step, a step of regenerating the electrodes by desorbing the ions adsorbed to the electrodes during the CDI process.

5. The method according to claim 1, further comprising, before performing the first step, a step of preparing a process liquid containing the fermentation product by fermenting with microbial cells.

6. The method according to claim 5, further comprising, before performing the first step, a step of crystallizing and dissolving the fermentation product contained in the process liquid.

7. An apparatus for producing a fermentation product, the apparatus comprising: a capacitive deionization (CDI) apparatus for preparing a deionized process liquid by removing ions from a process liquid containing the fermentation product; and a spray-drying apparatus for obtaining the fermentation product from the deionized process liquid prepared by the CDI apparatus without recrystallization.

8. The apparatus according to claim 7, wherein the CDI apparatus includes an electrode element for adsorbing and removing the ions contained in the process liquid when an electric power is applied; and a flow path element configured such that the process liquid is discharged to the outside of the CDI apparatus after contacting the electrode element.

9. A method for producing a fermentation product, the method comprising: a first step of preparing a deionized process liquid by removing ions from a process liquid containing the fermentation product through capacitive deionization (CDI); and a third step of obtaining the fermentation product in crystalline form from the deionized process liquid.

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